From: Tejun Heo <tj@kernel.org>
To: Josh Hunt <joshhunt00@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org, Vivek Goyal <vgoyal@redhat.com>
Subject: Re: multi-second application stall in open()
Date: Tue, 26 Jun 2012 13:43:22 -0700 [thread overview]
Message-ID: <20120626204322.GV3869@google.com> (raw)
In-Reply-To: <CAKA=qzZ_KhRbH6F4-TWvSAWiJyDsDrz4oUO5WppoMgWNEhyZmg@mail.gmail.com>
Hello,
On Tue, Jun 26, 2012 at 10:18:04AM -0500, Josh Hunt wrote:
> Do you have any suggestions on how to debug this?
>
> I did "perf record -a -e workqueue:*" and grabbed some tracepoint
> data, but it's hard to correlate when these events are occurring in
> the blktrace logs. Will keep investigating.
Yeah, as Vivek said, it would be better to get both traces through
perf instead of using blktrace. queue_work and execute_start TPs
print out the function pointer. Only printing out entries which match
the unplug_work would reduce a lot of noise - you can grep
cfq_kick_queue's address from /proc/kallsyms and set up
/sys/kernel/debug/tracing/events/workqueue/EVENT/filter - "echo
function==0xFUNCADDR > /sys/kernel/debug.../filter". Not sure how to
do that with perf tho.
Ooh, you posted another message. Will continue there.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-06-26 20:43 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-06 21:56 multi-second application stall in open() Josh Hunt
2012-03-07 13:43 ` Josh Hunt
2012-03-07 16:28 ` Vivek Goyal
2012-03-07 18:56 ` Jens Axboe
2012-03-07 19:56 ` Vivek Goyal
2012-03-07 21:08 ` Josh Hunt
2012-03-08 22:22 ` Josh Hunt
2012-03-08 23:40 ` Vivek Goyal
[not found] ` <CAKA=qzbsL9UVYLZ3=hoT-1jfp=v=_Sr=h+YeHu0qAA=Ko_7P6w@mail.gmail.com>
2012-06-21 19:26 ` Josh Hunt
2012-06-21 20:32 ` Vivek Goyal
2012-06-21 20:36 ` Tejun Heo
2012-06-21 21:28 ` Josh Hunt
2012-06-21 21:32 ` Tejun Heo
2012-06-21 21:48 ` Rakesh Iyer
[not found] ` <CAOT6A4-a49wLHcQepUxJCDxOxfnSTEWa72OweLsmrea85OyrCg@mail.gmail.com>
2012-06-22 14:15 ` Vivek Goyal
2012-06-21 21:11 ` Josh Hunt
2012-06-22 14:12 ` Vivek Goyal
2012-06-22 20:05 ` Josh Hunt
2012-06-22 20:22 ` Josh Hunt
2012-06-22 20:42 ` Vivek Goyal
2012-06-22 20:53 ` Josh Hunt
2012-06-22 20:57 ` Josh Hunt
2012-06-22 21:34 ` Josh Hunt
2012-06-25 13:30 ` Vivek Goyal
2012-06-25 16:22 ` Josh Hunt
2012-06-25 21:18 ` Vivek Goyal
2012-06-25 23:05 ` Josh Hunt
2012-06-26 4:01 ` Josh Hunt
2012-06-26 12:59 ` Vivek Goyal
2012-06-26 15:18 ` Josh Hunt
2012-06-26 15:53 ` Vivek Goyal
2012-06-26 20:37 ` Josh Hunt
2012-06-26 20:56 ` Tejun Heo
[not found] ` <CAKA=qzbBtteDjHiPogCvN5jOSiPrDxx=vn96p02bXUy=6=jAgA@mail.gmail.com>
2012-06-26 23:44 ` Josh Hunt
2012-06-27 17:21 ` Josh Hunt
2012-06-27 17:38 ` Tejun Heo
2012-06-27 17:44 ` Josh Hunt
2012-06-27 17:54 ` Tejun Heo
2012-06-27 17:59 ` Josh Hunt
2012-06-29 23:02 ` Tejun Heo
2012-06-30 0:37 ` Josh Hunt
2012-07-04 1:12 ` Tejun Heo
2012-07-18 17:48 ` Tejun Heo
2012-06-26 20:43 ` Tejun Heo [this message]
2012-06-25 17:26 ` Tejun Heo
2012-03-07 19:47 ` Josh Hunt
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